I am using automated average costing. My understanding is that product cost should not change except if I made a new purchase and received it. However, the product cost changes after Inventory adjustment which to my knowledge should not affect the cost. Its affecting my COGS and inventory valuation. Also I noticed it only happens if the counted products are more than on-hand, when its the other way around the cost doesn't get affected. Also there hasn't been any journal entries or manual product cost changes that happened to affect the cost. Only inventory adjustments.